Stupid ending *spoiler*
You'd think that unknown monsters like that would a) not be so populated b) wouldn't expose themselves in broad daylight along a highway otherwise they wouldn't be unknown quite fast.
Also, she ran for like an hour or two it seems and persevered so much to just breakdown and give up like that in the end. The highway was a stone throw away, she could have ran for it. She kept running when she doesn't know where she's going and when she finally sees a road, she gave up. what? Just a stupid, highly unbelievable ending.